1. Field of the Invention
The present invention relates to a black key for a keyboard instrument, such as a piano, and more particularly to a black key incorporating a weight in a black key cover so as to obtain desired touch weight, and a method of manufacturing the black key cover.
2. Description of the Related Art
Conventionally, as a black key of this kind, one disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2001-147686 is known. This black key includes a slim wooden key body having a rectangular shape in cross section, and a black key cover mounted on a front portion of an upper surface of the key body. The black key cover is comprised of a black key cover body and a weight received therein. The key body is swingably supported at a central portion thereof by a balance rail pin. The black key cover body, which is made of a molded article of a synthetic resin, such as phenol, is formed to have a hollow shape opening downward, and has a hollow portion having a trapezoid shape in cross section. Further, the weight has a shape complementary to the hollow portion of the black key cover body such that it is fitted into the hollow portion.
In assembling the black key configured as above, first, the weight is fitted into the hollow portion of the black key cover body, and is bonded to the same. After that, the black key cover of the black key is bonded to the front portion of the upper surface of the key body, which completes the assembly of the black key. In this case, to ensure excellent bonding of the black key cover to the key body, it is preferable that the weight is mounted in the black key cover body in a state slightly indented from the lower surface of the black key cover body, whereafter the lower surface of the black key cover body is cut such that the respective lower surfaces of the black key cover body and the weight make a flat and smooth surface.
In this black key, it is necessary to carry out the steps of making the black key cover body and the weight separately from each other, fitting the weight into the hollow portion of the black key cover body, and bonding the weight to the black key cover body, which increases the manufacturing costs of the black key cover. Further, as described above, if the weight is mounted in the black key cover body in the state slightly indented from the lower surface of the black key cover body, the black key cover is bonded to the key body only via the lower surface of the black key cover body, resulting in a reduced bonding area. As a result, if the black key cover is not properly bonded to the key body, there is a fear that the black key cover comes off the key body. Further, in the above-described case, if the weight becomes separate from the black key cover body e.g. due to faulty bonding thereof, the weight rattles within the black key cover body when the black key is depressed, thereby causing offensive noise.